1. Field of the Invention
The present invention relates in general to an automatic device for assembling fiber collimators.
2. Description of the Related Art
In a fiber-optic link, an optical fiber is connected to another optical fiber via fusion splice or via a connector plus an adapter. However, an optical fiber has a limitation of a numerical aperture so that a laser beam diverges at an angle when propagating from the optical fiber. To prevent the laser beam from diverging, a fiber collimator, a very important element in communication, has been invented.
A typical fiber collimator includes a pigtail, a GRIN (GRaded INdex) lens and a tubular holder. U.S. Pat. No. 6,019,522 discloses the structure of a fiber collimator and the epoxy used therein. U.S. Pat. No. 6,023,542 discloses a fiber collimator including a GRIN lens, and a fiberoptic coupler including the fiber collimator. U.S. Pat. No. 6,148,126 discloses a dual-fiber optical collimator and a method of assembling the collimator. U.S. Pat. No. 5,588,077 discloses a rotary joint including a fiber collimator. However, no prior art is related to an automatic device for assembling fiber collimators.
Energy loss is an important parameter for a fiber collimator. Generally, energy loss arises from misalignment of the ferrule with the GRIN lens and also arises from the parts themselves of the fiber collimator. The energy loss arising from the parts of the fiber collimator is unavoidable. To improve energy loss, therefore, manufacturers focus on the misalignment of the ferrule with the GRIN lens.
An object of the present invention is to provide an automatic device for assembling fiber collimators to promote the efficiency of manufacture and yield.
In the present invention, the fiber collimator includes a xe2x80x9ctransparentxe2x80x9d tubular holder, an optical fiber having a first end surface disposed at an end of the tubular holder, and a GRIN lens having a second end surface disposed at the other end of the tubular holder. The automatic device includes an image pick-up device, a processor, a first driving table for rotating and moving the optical fiber, and a second driving table for rotating and moving the GRIN lens. The image pick-up device films the first and second end surfaces, and outputs image data corresponding to the first and second end surfaces. The processor receives and processes the image data to control the first and second driving table to rotate so that the first and second end surfaces are parallel to each other, and control the first and second driving table to move so that a distance between the first and second end surfaces is equal to a predetermined value.
By the automatic device for assembling fiber collimators, the efficiency of manufacture and the yield are greatly improved.